Embodiments of the disclosed technology relate to a backlight module and a liquid crystal display (LCD) device.
In recently, liquid crystal displays (LCDs) are typical kind of flat panel displays, and thin film transistor liquid crystal displays (TFT-LCDs) are the mainstream type of LCDs. Backlight modules are important components for supplying light in liquid crystal displays when liquid crystal displays are operated, and generally can be classified into a direct type backlight module and a side light type backlight module. Compared with the side light type backlight module, the direct type backlight module is more suitable to be used in the liquid crystal display that requires high brightness and is of a large size, for example, liquid crystal television, etc.
FIG. 1 is a schematic structure view of a conventional direct type backlight module. As shown in FIG. 1, the conventional direct type backlight module includes a back plate 10, a frame 20, a light source 30 and a diffusion plate 40, wherein light sources 30 are disposed on the back plate 10 for supplying light; the frame 20 is disposed around the back plate 10 to hold the diffusion plate 40 between the edge portion of the back plate 10 and the frame 20 and also to accommodate a liquid crystal panel; the diffusion plate 40 is used for diffusing the light emitted from the light source 30, so that the light emitted from the light source 30 can be uniformly irradiated on the liquid crystal panel located on the frame 20, and thus the uniform light can be provided to the liquid crystal panel for display. Meanwhile, in order to protect the diffusion plate 40 from the heat generated by the light sources 30, a certain gap is maintained between the diffusion plate 40 and the light sources 30. For guaranteeing the horizontal optical property of the diffusion plate 40 and preventing the central portions of the diffusion plate 40 from sinking, a plurality of struts 50 are disposed with an interval in the central portion of the back plate 10 in the direct type backlight module to support the diffusion plate 40. Thus, the diffusion plate 40 can avoid recessed portions at its central region due to gravity, and the horizontal optical property of the diffusion plate 40 can be guaranteed.
However, in the conventional direct type backlight module, the diffusion plate 40 is directly placed between the back plate 10 and the frame 30, and is not fixed in the horizontal direction, so the diffusion plate 40 is not fixed firmly. For example, when a vibration test is preformed on the backlight module or the liquid crystal display with the backlight module or the liquid crystal display is in a vibration state, the diffusion plate 40 and the frame 30 for fixing the diffusion plate may rub each other to generate debris or chipping. The generated debris influences the property of the diffusion plate 40 and the liquid crystal panel, resulting in poor display in the liquid crystal display. Further, since the diffusion plate 40 is supported by the plurality of struts disposed on the back plate, the arrangement of the struts may effect the optical property of the light sources, and when the liquid crystal display is in a vibrating state, the struts may rub the diffusion plate to generate debris or chipping, which also influences the property of the diffusion plate 40 and the liquid crystal display. In a drop test, the liquid crystal panel also may be impacted by the struts and pixels may be damaged, which results in white point phenomenon and poor display in the liquid crystal display.